JP2021161464A - Preparation method of copper smelting raw material - Google Patents

Abstract

To provide a mixing method of a raw material to be treated in copper smelting capable of homogeneously mixing a wet raw material containing miscellaneous raw materials and copper concentrate.SOLUTION: A method for preparing a copper smelting raw material consisting of a wet raw material containing miscellaneous raw materials and a copper concentrate comprises a premixing process S1 to obtain a wet raw material R3 by premixing the miscellaneous raw material R1 in a wet state and a part of the copper concentrate R2, a meeting-parting process S2 for converging to one position below by alternately falling from one terminal of the belt conveyor 2, after the wet raw material R3 and the residue R2' of the copper concentrate are alternately cut at one terminal of the belt conveyor 2 and these are separately spread on separate belt surfaces, and a dispersing process S3 of alternately superposing one layer at a time at the one position while dispersing the wet raw material R3 and the copper concentrate R2 alternately falling from the terminal of the belt conveyor 2 by utilizing a positional energy at the time of falling.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for preparing a copper smelting raw material composed of a copper concentrate and a wet miscellaneous raw material.

In dry copper smelting, copper concentrate, which is mainly composed of chalcopyrite whose copper grade has been improved to about 30% by pretreatment such as flotation, is used as a raw material and charged into a smelting furnace such as a flash smelting furnace. High-quality copper is manufactured by subjecting it to processing such as burning. In the above smelting furnace, exhaust gas containing a large amount of sulfur dioxide is generated, and the exhaust gas is sent to a sulfuric acid factory as a raw material for sulfuric acid. In this sulfuric acid factory, waste acid containing copper and heavy metals is generated as impurities in the manufacturing process. Therefore, a sulfide is added to the waste acid to precipitate these copper and heavy metals, and then solid-liquid separation means such as filtration is used. It is collected in the form of muddy starch.

Since the above-mentioned muddy starch contains copper, it is mixed with the above-mentioned copper concentrate as a miscellaneous raw material and charged into a copper furnace. At that time, since the above-mentioned miscellaneous raw materials are different from copper concentrate in properties such as composition and particle size, the operation of the smelting furnace is not possible by mixing with copper concentrate so that the properties of the raw materials are almost uniform. It is desirable to prevent it from becoming stable. As a method of mixing copper concentrate and miscellaneous raw materials so that the properties of the raw materials are substantially uniform, for example, a method of mixing using a shovel loader while visually checking the mixed state is known.

Further, as disclosed in Patent Document 1, a technique has been proposed in which miscellaneous raw materials are quantitatively cut out and added onto a copper concentrate being conveyed by a belt conveyor. Further, although it is not intended for muddy starch, Patent Document 2 states that different types of solid particles are spread on a plurality of belt conveyors and at the same position from each discharge portion of these belt conveyors. A technique for dropping the solid particles has been proposed.

Japanese Unexamined Patent Publication No. 09-087760 Japanese Unexamined Patent Publication No. 2011-0111105

The above miscellaneous raw materials have the advantages of containing copper and being available at low cost, but in general, miscellaneous raw materials are difficult to handle, and many of them have high impurity grades, resulting in variations in properties. be. Therefore, usually, a large amount of a single type of miscellaneous raw materials is not mixed with copper concentrate, and many kinds of miscellaneous raw materials are mixed with copper concentrate at the same time. In this way, when adding various kinds of miscellaneous raw materials to copper concentrate at the same time, in order to apply the technique of Patent Document 1, a plurality of cutting devices corresponding to each of these various kinds of miscellaneous raw materials are required. Therefore, the equipment cost is high.

Further, in the technique of Patent Document 2, when at least one kind of solid particles of different kinds is in a wet state like the above-mentioned muddy starch, it adheres to a belt conveyor and cutting out becomes intermittent. It becomes unstable. Therefore, it is difficult to mix the raw materials so that the properties are uniform. In this case, it is conceivable to dry the wet solid particles in advance to the extent that they do not adhere to the belt conveyor, but the muddy starch recovered from the waste acid of the above sulfuric acid factory absorbs moisture such as sulfate. Since it contains a sexual component, it is difficult to dry, and if the amount of heating is increased to promote drying, it evaporates violently, so that solid particles may scatter with the water vapor generated at that time.

As described above, when it is not desirable to provide a plurality of cutting devices corresponding to each of the various kinds of raw materials, or when at least one of the various kinds of raw materials is in a wet state, these various kinds of raw materials are used. In order to mix as uniformly as possible, it is preferable to use an excavator loader as described above. However, in order to mix uniformly with the excavator loader, it is necessary to take a long time to perform a time-consuming work such as finding a portion where the mixing is insufficient and stirring the mixture many times until the mixture is sufficiently mixed. Further, depending on the skill level of the excavator loader driver's mixing operation, for example, the degree of mixing of the wet solid particles and the dry solid particles varies, and if the mixing is insufficient, the composition is formed in the smelting furnace. Frequently fluctuated, and the operation of the smelting furnace was sometimes unstable.

The present invention has been made in view of the problems of the above-mentioned conventional mixing method, and it is not necessary to perform the time-consuming mixing work using the excavator loader for a long time, and the mixing work of the operator is performed. It is an object of the present invention to provide a method for preparing a copper smelting raw material capable of uniformly mixing a wet raw material containing miscellaneous raw materials and a copper concentrate without being influenced by proficiency.

In order to achieve the above object, the method for preparing a copper smelting raw material according to the present invention is a method for preparing a copper smelting raw material composed of a wet raw material containing miscellaneous raw materials and copper concentrate, and the wet raw material and the copper refinement. Having a separation step in which ore is alternately cut out at one end of a belt conveyor, spread separately on the belt surface, and then alternately dropped from the end of the belt conveyor and merged with one place below it. It is characterized by.

According to the present invention, it is not necessary to perform a time-consuming mixing operation using a shovel loader for a long time, and a wet raw material containing miscellaneous raw materials is not affected by the proficiency level of the mixing operation of the operator. And copper concentrate can be mixed uniformly.

It is a block flow figure which shows the preparation method of the copper smelting raw material which concerns on embodiment of this invention. It is a schematic process flow diagram of the copper smelting raw material preparation method which concerns on embodiment of this invention. It is a graph which shows the trend of the copper grade of the mat produced by using the copper refining raw material prepared in the Example and the comparative example of this invention.

Hereinafter, embodiments of the method for preparing a copper smelting raw material according to the present invention will be described in detail with reference to the drawings. The preparation method of the embodiment of the present invention targets two types of granular raw materials to be processed in copper smelting, one of which is a moist and wet miscellaneous raw material, which is mainly It consists of precipitates produced by adding a sulfide agent to the waste acid discharged from the sulfuric acid factory. The other of the above two types of granular raw materials is usually composed of a dry copper concentrate. The miscellaneous raw materials are not limited to the precipitates produced in the sulfuric acid plant, but include copper-containing substances produced in other processes of the copper smelting plant such as decopper slime and copper slag in the electrowinning process. You may be.

As shown in FIG. 1, the method for preparing a copper smelting raw material according to an embodiment of the present invention includes a premixing step S1 in which the above miscellaneous raw materials are premixed with a part of copper concentrate, and a wetness obtained by the premixing. The raw material and the rest of the copper concentrate are alternately cut out at one end of the belt conveyor, spread separately on the belt surface, and then alternately dropped from the end of the belt conveyor to one place below it. The wetting raw material and copper concentrate that alternately fall from the end of the belt conveyor and the disengagement step S2 that merges with the conveyor belt are alternately dispersed one layer at a time while utilizing the position energy at the time of the fall. The cutting belt conveyor includes both the stacking dispersion step S3, the additional separation / dispersion step S4 performed one or more times as necessary, and the wet raw material and concentrate merging at the one location. It has a final homogenization step S5 which is cut out little by little and homogenized. Hereinafter, each of these steps will be described in detail with reference to FIG.

1. 1. Premixing step S1
In first premixing step S1, and a part of the coarse material R ₁ and copper concentrate R ₂ in the wet state were premixed to obtain a premixed raw material R ₃ are. In this premixing step S1, it is not necessary to mix these two kinds of raw materials until they are almost completely uniform, and the belt conveyor in the post-step union step S2 with the miscellaneous raw materials having a high degree of humidity and easily adhering to be unmixed. Mix to the extent that it is not introduced alone. A known mixing method can be used for this premixing, for example, the work of applying force to the miscellaneous raw materials and the copper concentrate using a shovel loader to spread the miscellaneous raw materials and the copper concentrate on the ground or the floor surface. Efficient premixing can be achieved by repeating the work of collecting the spread miscellaneous raw materials and the copper concentrate once or a plurality of times.

In this way, by using the excavator loader, even if the miscellaneous raw materials and copper concentrate contain lumps such as clay, the lumps can be finely divided. Further, since the copper concentrate can be attached to the surface of the finely divided miscellaneous raw materials, it is possible to prevent the particles of the miscellaneous raw materials in the wet state from adhering again and returning to the agglomerates. The amount of copper concentrate to be blended with the miscellaneous raw materials in the premixing step S1 is preferably adjusted appropriately depending on the properties such as the water content, particle size, composition, and hydrophilicity of the miscellaneous raw materials, but generally, the miscellaneous raw materials 1 It is preferable to mix copper concentrate in a ratio of 1 to 10 parts by mass with respect to parts by mass.

2. Separation process S2
In Rigo step S2, wetting materials and the remainder after the part is used in the above premixing process S1 of copper concentrate R ₂ containing coarse material is premixed feedstock R ₃ obtained in the above premixing process S1 preferably the copper concentrates R _{2 'of} cutting alternately on one end of the cutting device 1 via the belt conveyor 2 consisting of a hopper and metering feeder. At that time, by operating the belt conveyor 2, these wet raw materials and copper concentrate are separately spread on the belt surface, and then dropped from the end portion to be the transport destination of the belt conveyor 2 and below the belt conveyor 2. Can be merged into one place. In this way, by alternately cutting out two types of raw materials at one end of the belt conveyor 2, these two types are placed in different regions on the belt surface without changing the cutting position or providing a plurality of cutting devices. The raw materials of each can be expanded.

By merging the two types of raw materials spread out in different regions from each other at the transport destination of the belt conveyor 2, the particles are in a mixed state in which the particles are more mixed than before the cutting. Thus, if each of the raw material, for example, in the premixed feedstock R ₃ has unevenly distributed, it proceeds to a more mixed directions, a more uniform mixed state. The number of belt conveyors 2 used in the disengagement step S2 may be one, but a plurality of continuous belt conveyors may be used. Further, as the belt conveyor 2, a tripper conveyor may be used as shown in the second unit of FIG. The transfer destination of the belt conveyor 2 may be on the ground or the floor surface, or may be, for example, a container such as a hopper or a tank, or a transfer device such as a belt conveyor or a screw conveyor.

3. 3. Dispersion step S3
In the dispersion step S3, each of the wet raw material and the copper concentrate, which are alternately dropped from the belt conveyor 2 in the separation step S2, is dispersed by utilizing the potential energy at the time of the drop, and one layer is provided at the above-mentioned one location. Stack them alternately one by one. That is, the wet raw material and the copper concentrate are alternately dropped toward the one location, and as shown in FIG. 2, the wet raw material and the copper concentrate are alternately stacked one layer at a time. _A conical deposit consisting of 4 is formed. In this deposit, wet raw materials and copper concentrates that fall at different times will be arranged like annual rings on the same horizontal plane.

As described above, the wet material and copper concentrate falling from the belt conveyor 2 alternately, distributed by spreading in random directions along the top of the deposit of a substantially conical shape composed of mixed material R ₄ on the side surface. As a result, even if miscellaneous raw materials are unevenly distributed in the wet raw material, they are randomly spread and dispersed, and more uniformization is promoted. Subsequently copper concentrate to fall even along the side surface from the top of the deposit of a substantially conical shape of similar mixed raw material R ₄ distributed by spreading in a random direction. Further, when unevenness is formed on the side portion of the conical deposit by the wet raw material, the concave portion is filled or the convex portion is broken to spread the side portion while flattening it. In the above dispersion step S3, the larger the falling head, the farther each raw material spreads. Therefore, it is preferable to give a head from the viewpoint of more uniform mixing.

4. Additional separation and dispersion step S4
In the additional separation / dispersion step S4, the wet raw material and the copper concentrate merged at one location in the above dispersion step S3 are preferably scooped up with a shovel loader and cut out for additional separation / dispersion consisting of a hopper and a quantitative feeder. It is put into the device 3, cut out from here to one end of the additional disengagement and dispersion belt conveyor 4, spread on the belt surface, and then downward from the end on the opposite side of the additional disengagement and dispersion belt conveyor 4. It is dropped toward the surface and is dispersed by utilizing its position energy, and is merged with the one below. As a result, the homogenization can be further promoted.

This additional separation / dispersion step S4 may not be performed if there is no particular operational problem in the dry copper smelting after the drying step of the subsequent step, or may be performed twice or more. When the additional disengagement / dispersion step S4 is performed twice or more, an arbitrary part of the deposit formed by merging at one place below the end of the additional disengagement / dispersion belt conveyor 4 is sampled and used as a wet raw material. The number of times can be determined by using as an index whether or not the mixing ratio of copper concentrate is almost the same.

Since the behavior of the individual solid particles constituting the wet raw material and the copper concentrate at the time of falling is statistical, it is not possible to predict the moving direction and the moving distance when the individual solid particles are dispersed from the falling point. Therefore, for example, when the additional disengagement / dispersion step S4 is performed twice or more, if the head dropped from the end portion of the additional disengagement / dispersion belt conveyor 4 is the same each time, the first and second times it spreads from the drop point. Solid particles having the same movement distance and moving in the opposite direction are generated, and efficient mixing cannot be performed. Therefore, when the additional separation / dispersion step is performed twice or more, for example, the head when dropped from the additional separation / dispersion belt conveyor 4 is set so that the moving distance when the solid particles spread is different between the first time and the second time. It is desirable to change it every time.

5. Final homogenization step S5
In the final homogenization step S5, a substantially conical deposit in which the wet raw material and the copper concentrate formed in the dispersion step S3 are alternately stacked in layers, or the wetting formed in the additional separation / dispersion step S4. From a substantially conical deposit in which the raw material and copper concentrate are uniformly mixed, these wet raw materials and copper concentrate are transferred to the final belt conveyor 6 via a final cutting device 5 including a hopper and a quantitative feeder. Cut out little by little. As a means for supplying the deposit to the final cutting device 5, a large heavy machine such as an excavator loader is preferable, and by using such a large heavy machine, the wet raw material and the copper concentrate can be separated. Since both can be scooped out so as to be included, uniformization can be performed more efficiently.

The wet raw material and copper concentrate scooped up by the excavator loader as described above are put into the hopper of the final cutting device 5 and spread in the hopper. As a result, for example, even if the miscellaneous raw materials are unevenly distributed in the layer of the wet raw material of the deposit, they are dispersed and spread throughout, and the mixture approaches a more uniform mixture. After that, the wet raw material and the copper concentrate in this mixed state are further mixed by the quantitative feeder, so that the state becomes more uniform than the state of the deposit before the final homogenization step S5.

As described above, according to the preparation method of the embodiment of the present invention, a copper smelting raw material mixed more uniformly than the conventional mixing method can be stably prepared. The wet miscellaneous raw materials targeted by the above preparation method are not particularly limited, and solid particles having various compositions and moisture contents can be used, and at least the surface thereof is wet. A more remarkable effect can be obtained. On the other hand, if the copper concentrate has a lower water content and lower adhesiveness and cohesiveness than the above-mentioned miscellaneous raw materials, a more remarkable effect can be obtained. Normally, copper concentrate is composed of solid particles that contain almost no water, and copper concentrate has a hydrophobic property that easily repels water, so even if part or all of it is wet, its water content. The rate remains in the low range, and proper mixing can prepare copper smelting raw materials with uniform properties.

It is known that the adhesiveness and cohesiveness of solid particles constituting miscellaneous raw materials handled in copper smelting are generally proportional to the water content of the solid particles. When the water content in the solid particles exceeds 50%, the adhesiveness and cohesiveness rapidly increase, and the solid particles tend to be in contact with each other. On the other hand, solid particles having a water content of about 0% to 50% have lower adhesiveness than the above-mentioned solid particles having a water content of more than 50%, and can be diffused over a wide range during mixing. Here, the water content is the mass ratio of water contained in the substance and is also referred to as the water content.

(Example 1)
Sandy copper concentrate (moisture content 8-10%) and clay-like small mass miscellaneous raw materials (moisture content 35-) that are precipitates produced by adding a sulfide agent to the waste acid discharged from the sulfuric acid factory. 65%) was prepared, and a raw material for copper smelting was prepared along the block flow of FIG. The additional separation / dispersion step S4 was not performed. The water content was calculated by measuring the mass of a partially collected sample before and after drying.

Specifically, first, as the premixing step S1, a premixed raw material was obtained by premixing using a shovel loader at a ratio of 5 parts by mass of copper concentrate to 1 part by mass of miscellaneous raw materials. Next, as the separation step S2, the premixed raw material was alternately charged into the hopper of the cutting device 1 at a ratio of 5 parts by mass of copper concentrate to 1 part by mass of the premixed raw material as shown in FIG. When the raw materials were charged alternately, almost all the raw materials charged immediately before were cut out and the inside of the hopper was emptied before the next raw material was charged.

By alternately charging the hopper in this way, the premixed raw material and the copper concentrate were alternately cut out on the belt conveyor 2. These premixed raw materials and copper concentrates alternately cut out on the belt conveyor 2 are separately spread on the belt surface of the belt conveyor 2 (general belt conveyor and subsequent tripper conveyor), and then the tripper. It was merged into one place by dropping it from the tip of the conveyor to an empty storage area of the mine.

When to merge into one place above, as a dispersion step S3, while dispersing on傾面substantially deposit conical shape composed of mixed material R ₄ to each homogenizing these premixed feed with copper concentrate 1 Layers were stacked alternately. Finally the final homogenization step S5, shovel loader to the premixed raw material and Dosei ore from deposits mixed material R ₄ consisting of a premix material and the copper concentrate formed in the storage are also included both After scooping up little by little and heating and drying with a rotary dryer 7 as a homogenizing raw material, the copper was smelted by charging it into a self-melting furnace. While continuing this operation for 2 days, mats (sulfides) produced from the flash smelting furnace were collected every 4 hours and their copper grades were analyzed. As a result, as shown by the solid line in FIG. 3, the analytical value of the copper grade remained almost constant.

(Comparative Example 1)
The same copper concentrate and miscellaneous raw materials as in Example 1 were separately transported to the mine without mixing with each other, and mixed by a shovel loader at the mine so as to have almost the same mixing ratio as in Example 1. Copper smelting was carried out in the same manner as in Example 1 except for the above. As a result, as shown by the dotted line in FIG. 3, the analytical values of the copper grade became more varied than in Example 1. It is considered that the variation in the copper grade of the product of the flash smelting furnace is caused by the variation in the copper grade of the charged material. Therefore, by adopting the preparation method of Example 1, the variation is more uniform than that of Comparative Example 1. It can be seen that the mixed copper smelting raw material can be charged into the flash smelting furnace.

1 Cutting device 2 Belt conveyor 3 Cutting device for additional separation and dropping 4 Belt conveyor for additional separation and dropping 5 Final cutting device 6 Final belt conveyor 7 Rotary dryer R ₁ Miscellaneous raw material R ₂ Copper concentrate R ₃ Premixed raw material R ₄ Mixed Raw Material S1 Pre-Mixing Step S2 Separation Step S3 Dispersion Step S4 Additional Separation Dispersion Step S5 Final Uniformization Step

Claims (8)

A method for preparing a copper smelting raw material composed of a wet raw material containing miscellaneous raw materials and a copper concentrate, in which the wet raw material and the copper concentrate are alternately cut out at one end of a belt conveyor and separately cut into belt surfaces. A method for preparing a copper smelting raw material, which comprises a separation step of spreading it upward and then alternately dropping it from the end of the belt conveyor and merging it at one place below the belt conveyor. The copper smelting raw material according to claim 1, further comprising a premixing step of premixing a wet miscellaneous raw material and a part of copper concentrate to obtain the wet raw material before the union step. Preparation method. The method for preparing a copper smelting raw material according to claim 2, wherein the premixing is performed with a shovel loader. Further having a dispersion step of alternately stacking the wet raw materials and copper concentrates that alternately fall from the end of the belt conveyor one layer at a time while dispersing them by utilizing the potential energy at the time of the fall. The method for preparing a copper smelting raw material according to any one of claims 1 to 3, which is characteristic. The wet raw material and copper concentrate that are merged at the one location are cut out at one end of the additional separation / dispersion belt conveyor, spread on the belt surface, and then below the end of the additional separation / dispersion belt conveyor. The preparation of the copper smelting raw material according to claim 4, wherein the additional separation / dispersion step of dropping the copper smelting material toward the conveyor belt and merging the copper smelting material into the lower one place while dispersing the copper smelting material is performed one or more times. Method. Any of claims 1 to 5, further comprising a final homogenization step of gradually cutting out to the final belt conveyor so that both the wet raw material and the copper concentrate that are merged at the one location are included. The method for preparing a copper smelting raw material according to item 1. The method for preparing a copper smelting raw material according to claim 6, wherein the wet raw material and the copper concentrate that have merged at the one location are scooped up by a shovel loader and introduced into the final belt conveyor. The method for preparing a copper smelting raw material according to any one of claims 1 to 7, wherein the copper concentrate is blended in an amount of 1 to 10 parts by mass with respect to 1 part by mass of the wet raw material.

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